1. Field of the Invention
The present invention relates to a recording and playing back device such as a hard disk drive, storage device, computer device, data processing method, and program sending device.
2. Background of the Invention
As is well known, hard disk drives are used frequently as a major location for storing data in computer devices. Recently, the storage capacity of hard disk drives has been increasing, bringing with it dramatic increases in the recording density of recording disks. As a result, the radial distance between tracks on a recording disk has been getting shorter. Consequently, reading data by the head requires higher positioning accuracy on the track where desired data is stored, making data read conditions severer from year to year.
In such hard disk devices, if a data read operation from a recording disk fails for some reason or other, an attempt to read data is made again (so-called “retry”). Since making unlimited number of retries may cause data corruption or the like, an upper limit is normally placed on the number of retries so that a read error will result when this limit is reached. As shown in FIG. 3, at the time of when reading data (Steps S601 and S602), even if the number of retries made before data is read successfully does not reach the upper limit, if it exceeds a predetermined reference number (<upper limit) (Step S603), a so-called “reassign process” is performed (Step S604). This is the process of transferring data stored on a recording disk from its original sectors to other sectors to protect the data.
However, if a reassign process is repeated many times, data many be scattered over the recording disk. If data to be read successively are scattered over different tracks, in particular, the head must move among tracks frequently, resulting in reduced read performance.
Such a problem is not limited to hard disk drives, but it is common to read operations from various storage media.
The present invention has been achieved to solve such a technical problem. Its object is to provide a recording and playing back device, storage device, computer device, data processing method, and program sending device that can effectively protect the data stored on storage media and storage disks.